diff -ruN a/src/header/mod.rs b/src/header/mod.rs
--- a/src/header/mod.rs	2026-04-15 09:58:03.811510680 +0100
+++ b/src/header/mod.rs	2026-04-15 09:59:40.902089070 +0100
@@ -103,6 +103,7 @@
 pub mod sys_stat;
 pub mod sys_statvfs;
 pub mod sys_time;
+pub mod sys_timerfd;
 #[deprecated]
 pub mod sys_timeb;
 //pub mod sys_times;
diff -ruN a/src/header/sys_timerfd/cbindgen.toml b/src/header/sys_timerfd/cbindgen.toml
--- a/src/header/sys_timerfd/cbindgen.toml	1970-01-01 00:00:00.000000000 +0000
+++ b/src/header/sys_timerfd/cbindgen.toml	2026-04-15 09:59:40.902120449 +0100
@@ -0,0 +1,12 @@
+sys_includes = ["time.h"]
+include_guard = "_SYS_TIMERFD_H"
+language = "C"
+style = "Tag"
+no_includes = true
+cpp_compat = true
+
+[enum]
+prefix_with_name = true
+
+[export.rename]
+"itimerspec" = "struct itimerspec"
diff -ruN a/src/header/sys_timerfd/mod.rs b/src/header/sys_timerfd/mod.rs
--- a/src/header/sys_timerfd/mod.rs	1970-01-01 00:00:00.000000000 +0000
+++ b/src/header/sys_timerfd/mod.rs	2026-04-15 09:59:40.902160103 +0100
@@ -0,0 +1,91 @@
+//! `sys/timerfd.h` implementation.
+//!
+//! Non-POSIX, see <https://man7.org/linux/man-pages/man2/timerfd_create.2.html>.
+
+use alloc::format;
+use core::{mem, slice};
+
+use crate::{
+    c_str::{CStr, CString},
+    error::{Errno, ResultExt},
+    header::{
+        bits_timespec::timespec,
+        errno::{EFAULT, EINVAL, EIO},
+        fcntl::{O_CLOEXEC, O_NONBLOCK, O_RDWR},
+    },
+    platform::{
+        Pal, Sys,
+        types::{c_int, clockid_t},
+    },
+};
+
+pub use crate::header::time::itimerspec;
+
+pub const TFD_CLOEXEC: c_int = 0x80000;
+pub const TFD_NONBLOCK: c_int = 0x800;
+pub const TFD_TIMER_ABSTIME: c_int = 0x1;
+pub const TFD_TIMER_CANCEL_ON_SET: c_int = 0x2;
+
+fn read_exact(fd: c_int, buf: &mut [u8]) -> Result<(), Errno> {
+    match Sys::read(fd, buf)? {
+        n if n == buf.len() => Ok(()),
+        _ => Err(Errno(EIO)),
+    }
+}
+
+fn write_exact(fd: c_int, buf: &[u8]) -> Result<(), Errno> {
+    match Sys::write(fd, buf)? {
+        n if n == buf.len() => Ok(()),
+        _ => Err(Errno(EIO)),
+    }
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn timerfd_create(clockid: clockid_t, flags: c_int) -> c_int {
+    let supported = TFD_CLOEXEC | TFD_NONBLOCK;
+    if flags & !supported != 0 {
+        return Err::<c_int, _>(Errno(EINVAL)).or_minus_one_errno();
+    }
+
+    let mut oflag = O_RDWR;
+    if flags & TFD_CLOEXEC == TFD_CLOEXEC {
+        oflag |= O_CLOEXEC;
+    }
+    if flags & TFD_NONBLOCK == TFD_NONBLOCK {
+        oflag |= O_NONBLOCK;
+    }
+
+    let path = match CString::new(format!("/scheme/time/{clockid}")) {
+        Ok(path) => path,
+        Err(_) => return Err::<c_int, _>(Errno(EINVAL)).or_minus_one_errno(),
+    };
+    Sys::open(CStr::borrow(&path), oflag, 0).or_minus_one_errno()
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn timerfd_settime(fd: c_int, flags: c_int, new: *const itimerspec, old: *mut itimerspec) -> c_int {
+    let supported = TFD_TIMER_ABSTIME;
+    if flags & !supported != 0 {
+        return Err::<c_int, _>(Errno(EINVAL)).or_minus_one_errno();
+    }
+    if new.is_null() {
+        return Err::<c_int, _>(Errno(EFAULT)).or_minus_one_errno();
+    }
+    if !old.is_null() && unsafe { timerfd_gettime(fd, old) } < 0 {
+        return -1;
+    }
+    let spec = unsafe { &*new };
+    let buf = unsafe { slice::from_raw_parts((&raw const spec.it_value).cast::<u8>(), mem::size_of::<timespec>()) };
+    write_exact(fd, buf).map(|()| 0).or_minus_one_errno()
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn timerfd_gettime(fd: c_int, curr: *mut itimerspec) -> c_int {
+    if curr.is_null() {
+        return Err::<c_int, _>(Errno(EFAULT)).or_minus_one_errno();
+    }
+    let curr = unsafe { &mut *curr };
+    curr.it_interval = timespec::default();
+    let buf = unsafe { slice::from_raw_parts_mut((&raw mut curr.it_value).cast::<u8>(), mem::size_of::<timespec>()) };
+    read_exact(fd, buf).map(|()| 0).or_minus_one_errno()
+}